Question

find  median Marks  0-10   10-20   20-30    30- 40                40-50 Frequency   8     30    40   12   10​

Answer 1

Answer:

Marks

Students(f)

Cumulative frequency(cf)

10−20

12

12

20−30

35

12+35=47

30−40

45

47+45=92

40−50

25

92+25=117

50−60

13

117+13=130

n=Σf=130

2

n

=

2

130

=65

Median =l+

⎝

⎛

f

2

n

−cf

⎠

⎞

×h

n=Σf= Total number of frequency =130

2

n

=

2

20

=65

So, the median class is 30−40

L= Lower limit of the median class =30

cf= Cumulative frequency of the class preceding the median class =92

f= Frequency of the median class =45

h= class width=10

Therefore, Median =l+

⎝

⎛

f

2

n

−cf

⎠

⎞

×h

=30+

⎝

⎜

⎜

⎛

45

2

130

−92

⎠

⎟

⎟

⎞

×10

=30+(

45

65−92

)×10

=30−6

=24

Hence, the median is 24.